The invention pertains to inflatable springs and running gear lift devices for vehicles.
The advantages of air springs and lifters for vehicles include excellent cushioning and shock absorbing characteristics, variable control of the degree of support and quality of suspension, low cost, and adaptability, and a variety of air spring devices are commercially available for vehicle use.
One of the disadvantages of air springs presently available for use with heavy duty vehicles is the cost of such devices, and the inability to produce trouble free operation over long periods of time. The continued flexing and abrasion to which such devices are exposed often causes spring failure after a duration of usage considerably less than that achievable with mechanical vehicle suspension systems.
Air springs utilizing a plurality of inflatable compartments are known, and it is also known to form the springs of an elongated configuration, as shown in U.S. Pat. Nos. 2,756,048; 2,879,077 and 2,941,816. However, known inflatable vehicle springs of the aforementioned type are expensive since custom built molds and dies must be formed for each size and configuration, and as the size of a particular spring will vary for each model of vehicle, economics dictate that relatively high air spring production for a particular model must be achieved in order to provide a spring which is economically feasible.